How to be happy
by The Divine Comedian
Summary: The Patronus charm requires a happy memory. Harry Potter doesn't have many. Boom, third year AU. If he still wants to save the wizarding world, he needs to recover from his greatest failure. How?


**How to be happy**

* * *

 **Note:** I had what I thought was a mildly original idea about where Dementors come from, so I wrote a fic about it.

* * *

Three months into their third year, Defence Against the Dark Arts was still everyone's favourite subject.

"But Professor," said Hermione. "I don't understand. Where do Dementors come from? We learned in Muggle Studies that they're personifications of a Muggle concept, depression. Did they come from Muggles? Did Muggles catch depression from us? How does that even work?"

"No-one really knows what Dementors are, or where they came from," said Professor Lupin. He'd given up on steering the classroom discussion back to Redcaps - a Hogsmeade visit was coming up, and the Dementors still creeped most everyone out. Naturally there were questions.

"Some think they're evolved from Boggarts," continued Lupin. "They say a clever Boggart figured out that if it scared its victims, they would run away, but if hit them with sadness and despair – they wouldn't see the point. Easier to feast on their minds."

"Is that why no-one knows what's under their hoods?" said Hermione eagerly. "Because they're evolved from shape-shifters? Maybe they don't have a shape at all. They're just… clothes."

"Clothes and a mouth, Miss Granger," said Lupin, while the class collectively made a face. "That's all everyone knows. You asked whether they are what the Muggles know as depression. Maybe. It doesn't mean the Dementors came first. Remember, historically, humankind has had a lot to be depressed about. With evolution, sooner or later something is going to eat anything. Even happiness. With similar results."

"I'd love to delve deeper into the subject," breathed Hermione.

Lupin smiled. "How about you write an essay?" he said. "For extra credit?"

"Thank you, Professor," said Hermione. Next to Harry, Ron couldn't keep himself from snickering. Harry would have joined in – after all, count on Hermione to deliver an interaction so typically _her_ , even if she looked like she hadn't slept in a week – but Harry's last disastrous Patronus lesson was still fresh on his mind. He wished himself miles away.

* * *

St. Mungo's had a hidden wing. It wasn't on the floor plan, it didn't have a name, and there were no healers. What it had, according to Hermione, was wardens, the most haggard, silent wardens you could hire for minimum wage. Nobody knew how many rooms there were. Once or twice a year, a new door popped up, discreet as you like.

It really was extremely hidden, thought Harry. At thirteen, almost fourteen, he had a pretty good idea of how serious wizards could be about hiding what they didn't want others to see. This wing especially.

Serious. Ha.

Naturally, Hermione knew all about it, read about it in some ancient tome she brought to pass the long hours at Harry's sickbed (she'd given up on trying to discuss the end-of-year exams with Harry). She'd tutted and tsk'ed, but in the end, she could not resist imparting her knowledge on Harry.

Ron, similarly bored, but not as easily acquiesced by books, had tested an endless stream of ideas on how to find the hidden wing. He'd asked the paintings in the entrance hall for help (they'd refused it. Some hospital!). He'd followed the cleaners (and found a variety of broom cupboards). He'd tried behind the reverse polarity circulator in the Magical Accidents wing (and found nothing but a solid bit of wall).

In the end, Harry had decided to stealthily follow Professor Lupin after the former's brief and distracted sickbed visit, figuring if anyone had a motive to find that wing, it was Lupin. Of course, it meant that Ron and Hermione had already gone back to Hogwarts for the night, but then, he'd been meaning to go alone.

Admittedly, Harry was still not on top of his game. All remnants of stealth evaporated not five minutes into the operation when Lupin entered the lift (seriously? The hidden wing was accessible by lift?), turned, and looked directly at him.

"You're not supposed to see him," his teacher said mildly.

There was a world of explanations fighting for priority in Harry's mind, and Harry stumbled over all of them at once. It _was_ his fault. He should have done better. He should have tried harder, thought up a better memory, a happier memory. Naturally, what slipped out was a cheap shot.

"Are you?"

"I never thought to ask," said Lupin. He looked left and right along the hallway. At this time, it was nearly deserted. "You better come in before someone notices," Lupin added. He looked tired, worse than he had all year, but then, it had only been five days since the full moon.

But there was a new quality about Lupin, a certain to-hell-with-it attitude, not the unholy but ultimately light-hearted drive behind the Weasley twins and, he assumed, the Marauders before them. This was something graver, forged in tragedy. He'd been a wonderful teacher, but that, Harry realised now, was a role Lupin could slip in and out of with ease. He was something else now, but what?

The doors closed behind Harry, and up, up, up they went in silence. A disembodied voice announced the name of each story, except for the last one, above even the Hospital Shop. The lift opened after a long moment's hesitation.

In front of them was a long corridor with many doors. Some of the doors were ancient and wooden, with cracked metal fittings and old-fashioned keyholes; some were modern and sleek, with no doorknob anywhere. Some were in-between, neither old or new. Middle-aged.

"Professor," said Harry. The lift doors made a motion to close again and they hadn't even stepped out. Lupin held them open with one hand.

"Having second thoughts?" said Lupin. "Good. I'd be worried if you didn't."

"I want to go," said Harry quietly. "This is my fault, after all. If I had conjured a better Patronus –"

"No, Harry" said Lupin. "It's my fault. If I hadn't turned at that precise moment –"

"It's not your fault you're a werewolf!" said Harry.

"It's not your fault you're an unhappy teen," said Lupin. "Still, we both failed at playing the cards we were dealt with, didn't we? We were playing an unfair game, and this -" he gestured to the corridor, "this is losing. Let's go and face it."

There was nothing Harry could say to this. He felt, to his core, that Lupin was right, but it was still alien to him. Was self-blame part of growing up? Hermione had theorised that it was the result of whatever the Dementors had done to his brain before his feeble Patronus had chased them away.

Sort of chased them away.

Well, nudged them away, more like. Pretty much tapped their shoulders and pointed them towards an easier target, one without a wand and even fewer happy memories. Harry'd fallen unconscious in the mental storm of the Dementors' joy.

He followed Lupin along the corridor. The wardens were nowhere to be seen, but then, he figured the patients didn't ask for much. They needed feeding, they needed bathroom assistance, the occasional wash.

"It's a chain of events," said Lupin quietly, as they walked past door after door. "A chain of failures. You failed to conjure a strong Patronus because you couldn't hold on to a single happy memory. I failed to teach you because I underestimated what you'd have to overcome –"

"Professor –"

"You _listen,_ Harry. Albus failed when he put a traumatised one year old child in an abusive home. Voldemort failed to be human, and Peter, of course, failed to be brave. James failed his family when he trusted Peter over me. Severus failed to see past his childhood grudge, and we all failed when we bullied him in the first place. Justice failed Sirius when he was denied a trial and sent to Azkaban."

He paused, then started again. "Society failed when it silently consented," he said. "When we gave up our integrity and our values so we could sleep better at night. We were so scared then, we turned on ourselves. Because that was someone we could fight."

The anger in the man beside Harry was almost palpable. Well-controlled – and had he _met_ a man with better self-control? – Harry felt it could be a weapon.

"Is there anyone you don't blame, Professor?" said Harry.

Lupin looked at him. "You chose your friends well," he said. "They are clever, and brave. And you, Harry," he added, with a sigh, "you tried. You gave your best. That's more than most can say of themselves. They give their worst, or nothing at all. Sirius, of course, would have said it's results that count, but if it weren't for you three -"

He stopped in front of a door that looked brand-new, the frame neatly cut into the blinding white walls. There was a combination lock, and Harry watched Lupin put in the number. Only two digits. A twelve. What else would it be.

"If it weren't for you three," repeated Lupin, "I'd say let the scarecrows win. It's over. He can have this world, there's nothing I'd miss. I'm going in first."

"Professor?"

Lupin turned in the doorframe. "I've known him longer than you, and I despised him for a very long time," he said. "I have a lot to apologise for."

The door closed behind him, and before they did, Harry caught but a glimpse of the insides, brightly lit by the evening sun. _He_ was standing in front of the window, swaying slightly on the spot, not looking out the window, or at his visitor, or anywhere.

Then Harry was alone with his thoughts, in this corridor with nightmares behind each door. Or rather: the absence of nightmares, of dreams, of thoughts, of feelings. The absence of people. It didn't help that these rooms contained what was left of Death Eaters, murderers, child molesters.

Maybe that explained Dementors, he thought, remembering Hermione's questions in that Defence lesson, a hundred years ago. What else could you be, if these terrible souls were all you subsisted on?

How many innocents? How many falsely accused, like Sirius?

Yes, he did have second thoughts. Harry hardly even knew his godfather. It had felt like the best moment of his life when Sirius had asked him to come live with him – but that moment hadn't been joy, exactly. It had been relief. Like a chronic pain suddenly ending. A glimpse of a brighter future, without the ever-present knowledge that, however good he was, however brave, however clever, at the end of the year he'd have to go back to the Dursleys and be nothing. That escape hadn't been about Sirius. It hadn't been about the _to_ at all, it had been about the _from_.

Maybe Lupin was right, Harry thought. For the first time in his life, he was wondering whether growing up as he did had left him somehow defective. If he was even capable of being happy. If that dark cloud would ever go away.

Maybe. Sirius had seemed a bit crazy, sure, but a good person who had cared about Harry. He'd been his father's best friend, obviously, and Harry was sure they could have been friends, too, given more time. He'd _deserved_ more time with Sirius.

But this visit, did it count as more time? Moreover, did this count as Sirius?

It was so unfair he could scream, but he didn't dare. There was no sound from beyond these doors, and Harry was suddenly so much colder.

He knew that, when he opened his eyes, he would be back on the lake shore, trying again and again to conjure up that Patronus, feeble light against a flood of Dementors. On the other side of the lake, he _remembered_ losing to the Dementors, his mind quickly fraying at the edges. Harry never stood a chance because he'd already seen it going wrong once. Only Dumbledore's bold-faced lie that he could save them both _and_ the hippogriff had even made him go out and try.

They were here, too. Harry could feel their icy breath on his neck. He leant against the corridor wall for support, but his knees were already buckling underneath him. The bright light darkened. He heard his mother screaming, heard Sirius crying when the Dementors held him down and consumed him. In the corridor, Harry grabbed for his wand, but what was the point? He couldn't do it. He didn't have happy memories.

A chocolate bar was thrust in his face.

"I assume the healers explained about this?" said Lupin.

"Are the Dementors still here?" asked Harry. It was a bit brighter now that he wasn't alone, but he still felt moderately terrible.

"Apparently they didn't," said Lupin. He sighed. "Eat the chocolate, I'll explain."

Lupin, though, Harry thought. Lupin, who lost all his friends in that one terrible night and still carried on somehow for twelve years. Who had regained his best friend, only to lose him forever two hours later. And yet Harry's terrible, defective brain made this all about himself. What right did he even have?

He stared at the chocolate bar that had turned up in his hands.

"Get up, Harry," said Lupin. "They're not here. You were attacked by Dementors five days ago, and you came closer to being destroyed by them than half the prisoners in Azkaban. Of course you feel like they're following you around. The parts of your brain that know what happiness feels like haven't fully recovered yet. It takes time. And new memories."

Since Lupin was watching him quite intently, Harry clumsily unwrapped the chocolate and bit into it. He liked chocolate, he really did, but today the cloying sweet taste was but a mockery of a happy memory. He nearly choked.

"Are you sure you want to go in today?" said Lupin.

Harry swallowed. "I need to apologise, too," he said.

"If you think it'll help," said Lupin. "But if it's forgiveness you seek, you won't find it in there."

"What then?" asked Harry. "What did you find?"

"I didn't find anything," said Lupin. "I made a promise. But that's between me and him. Go now, I'll be right outside."

Harry got up from the floor, tapped in the number twelve with shaking hands. The door closed behind him before he could say anything else to Lupin.

It was like walking into a tomb. And like a tomb, there was nothing to be afraid of. It was not the departed that did terrible things, he reminded himself. It was the living that lurked in the shadows.

Sirius was still standing in that same spot, swaying slightly in a non-existent wind. His brilliant bright eyes were dull now. His hair had been washed, cut, and combed, his beard trimmed. He was wearing clean clothes and he'd obviously had a wash. Harrys thoughts recoiled at the thought, that someone has undressed this man, who hadn't asked for it, hadn't ask for any of this, who was swaying like a puppet.

"Sirius," he said quietly.

Of course, there was no response. Could the man even hear? Harry walked around him. Looked directly into his eyes, and the emptiness hit him. Of course, they'd explained this to him. There was nothing left of Sirius, nothing left of the man who was ready to die to save his parents but never got the chance. Who instead went to Azkaban for nothing, held on to his sanity for twelve years for nothing, was the first to break out of Azkaban for nothing, got his soul ripped from his body for nothing.

Nothing was what he was now.

"I have a friend, Hermione," said Harry, because the silence needed filling. "Remember her? She's given this a lot of thought, and she thinks there must be some basic program still running, right? Something that makes you breathe. Something that makes your heart beat. Something that keeps you balanced when you're standing. So maybe something is still listening. Maybe something is still outraged. And that's who I am speaking to. Because this is unfair, Sirius, I know it is, and I am outraged, and I am _sorry_."

There was no reaction.

"It was me," said Harry into the void. "I failed. I had the chance to save us. I even went back in time to try and save us again, but I failed again. I think you'd have been better off with someone else, like Ron. I bet he has loads of happy memories, I never really asked. I don't know about Hermione, maybe she thinks too much. But she's really clever, she might have pulled it off. Better than me, anyway. But then, if I had happy memories, if I'd have had any sort of normal life, you'd never have been in Azkaban in the first place, wouldn't you?"

There was no reaction. Outside the window, the sun was setting on them.

"At least Lupin seems to think so," said Harry, "Poor orphan Harry, raised by his evil aunt and uncle, of course he can't do a Patronus, right? But Lupin can, and he's had a messed-up childhood, too, and now he's a sad middle-aged man who's lost all his friends once, and then lost you again. I'd be _nothing_ without my friends, and he conjures Patronus after Patronus. Does he have nerves of steel?"

There was no reaction.

"I know you can't answer that," said Harry. "Because you're nothing, too, and it's my fault."

The silence got more oppressing. Harry could hear the Sirius-shaped thing breathing. Something was in there, he told himself. Even if all it could do was breathe in, and breathe out, and sway on the spot.

"I should have tried harder," said Harry. "I should have found a happier memory. There aren't many, you know. I thought I was happy when I found out I was a wizard, but that wasn't enough. I thought I was happy when I saw my parents in the Mirror of Erised, but Dumbledore explained that's more sad than happy. Sometimes I don't even know the difference. I think it's because it's the past, and it's over, but isn't that true for all happy memories? They're happy, but they're sad when they're over. I thought I was happy when Hagrid gave me that photo album of my parents, but I guess that's more sad than happy, too, isn't it?"

There was nothing but more silence. Sirius was still swaying on the spot. Did he ever do anything else? There were a chair and a desk and a bed in here, but did he know how to sit, how to lie down to sleep? Would he just keep standing here until his muscles failed?

"Hermione would tell you I'm not brilliant with words," said Harry. "And with, you know, feelings. She's very good with words, and sometimes she has feelings I don't even know the name of. But you're not very good with words either -"

A sudden burst of laughter bubbled up inside Harry, surprising him. Was he really _this_ bad with feelings?

"– So I suppose," he continued, "you won't mind. I want to tell you this. So here goes."

Silence.

"I was happy when you asked me to live with you," said Harry. "I thought I was stuck with the Dursleys for good, and now my long-lost godfather tells me I can have a proper home? I was all over that. You could have told me stories about my parents. There would have been proper Christmases and birthdays, and I could have told you about school, and you would have dropped me off at King's Cross. I think it would have been good. I was happy when you said that, proper happy, because it wasn't over, so it wasn't sad."

Silence.

"But I still couldn't summon the Patronus," said Harry. "It's not you, it's me. I was so happy I couldn't believe it. If the Dursleys taught me anything, it's that I can't escape them. I always have to go back. Even now. In two days I'll go back, and they won't know what happened, and if they know they won't care. Turns out I was right not to believe it, eh? I couldn't have this because I botched the Patronus, and I botched the Patronus _because_ I didn't believe I could have this."

Silence.

This was what Lupin meant, Harry realised. He wouldn't find forgiveness here. He would find nothing except what he'd brought with him. So maybe it was time to start looking.

"Hermione said I shouldn't be so hard on myself," said Harry. "Funny how she knows, I haven't told her half of what I just told you. Maybe I should. She's a pretty good listener. Not as good as you, though. And Lupin said that a lot of people failed, not just me. I think he is a bit angry with everyone at the moment. And he's right, a lot of people did fail before I had the chance to. I was just the last in line who could have done something to put it right. I am sorry, Sirius. You deserve so many apologies, but not just from me."

Silence.

"Not just from me," Harry repeated slowly. He had always known, but now, the words came, and with them, something else.

"And you know what," he added, "I deserve a lot of apologies, too. When I was offered a home, I didn't even know what to with that. I couldn't even imagine living with someone who didn't hate me. Why did the Dursleys hate me so much, Sirius? They did from the start. I was just a kid. Just a little kid. I didn't deserve this."

Harry didn't think of himself as a crier, Dudley and his cronies had beaten that out of him long ago. But after the week he'd had, what was the point in being brave? He cried now. He cried for that scared little boy, rescued from the ruins of his home where he'd cowered at arm's length from his mother's lifeless body. That child had needed love, and warmth, and safety. Instead he'd got the Dursleys, and he'd never get rid of them now.

He didn't think he'd ever talked so much about his feelings, not in all the years of his life taken together. That thing in front of him, that Sirius-shaped thing with eyes as empty as the sky, it was like a black hole, so devoid of thoughts and feelings and dreams that it dredged up all of Harry's, just to fill the void.

He realised he couldn't stay, it would suck him up.

"I need to go, I'm sorry," he said, drying his eyes with his sleeve. Even now, he could feel the pull. There was so much more he could say. He wondered what would happen if he never emerged from this door. Whether Lupin would come get him eventually.

And what Lupin would find inside.

The sun had now set, and the room was dark except for the city glow of London outside the window. It was noticeably colder now. Sirius hadn't moved, but now Harry could swear he saw the figure not just swaying, but shivering.

Maybe that was another thing that the basic program could do.

"You're cold, aren't you?" said Harry. He looked around the room. There were no clothes except what Sirius was wearing. There wasn't even a blanket on the bed. Harry hesitated for a long moment, then took off his own cloak, part of his school uniform. Sirius was a good bit taller than him, and broader in the shoulders, but he was still so thin and his body so yielding to Harry's gently tugging that was easy to wrap him up in it.

There was no reaction. Only the shivers abated.

"You can keep it," said Harry. "No need to say thanks."

Silence.

"Goodbye, Sirius," said Harry. "It was an honour meeting you."

Silence.

"I'll be back, I promise," said Harry, and turned to flee. The door opened easily, and Harry couldn't help but look back for a moment.

Silence, and Sirius was still swaying in the darkness, hood drawn up, lost, but not in thought.

* * *

Outside, Lupin was leaning against the wall. On his face was a thousand-yard stare that for a moment scared Harry. As if everyone was now a swaying puppet, save for him. But then, Lupin reacted.

"Did you find what you were looking for?"

"Found something," said Harry, not daring to look at Lupin directly. Then again, Lupin probably knew. "But that's between me and him."

Lupin nodded, and they set off, back along the long, lonely corridor. There were no wardens. Hermione had said there'd be wardens. But maybe they weren't needed.

"In the good old times," said Lupin, interrupting his thoughts, "before this wing was built, we'd put them to good use. Scarecrows in the wheat fields. Human bait when a Redcap infestation needed clearing. And of course, St. Mungo's always had a high demand for them, clinical trials, you see. Broke a lot of bones before they got the Skele-Gro formula right. Of course, that was four hundred years ago. Today, we would consider this unethical."

The tears were still fresh on Harry's face. "Exactly none of this is ethical," he said. His voice didn't break, he was thankful for that.

"True," said Lupin. Harry was reminded of his previous thoughts: That Lupin had slipped out of his teacher role, and into something else. But _what_?

"Why did you allow me to come?" said Harry. "You're a teacher, shouldn't you worry more?"

"I always teach by example," said Lupin. "And this is perhaps our most important lesson yet."

"You couldn't know what I'd talk to him about," said Harry.

"I have a pretty good idea," said Lupin. "So many people failed. If any of them had gotten it right, the task wouldn't have fallen to you, standing on the lake shore. None of this is your fault, Harry. It's good that you understand that. But that's not the lesson I intended."

"Then what is, Professor?"

"You are the student," said Lupin. "You tell me."

"Long day," said Harry. "A clue would be nice."

"You said it already," said Lupin. "You said, none of this is ethical."

Harry thought. Of course. That was the elephant in the room. Only wasn't not an elephant. It was an empty, Sirius-shaped husk.

"The system is broken," said Harry. "And it has been for a long, long time."

"That's what you're up against," said Lupin. "I know you're prepared to fight Lord Voldemort. You're prepared to fight the Death Eaters. A few days ago, you were prepared to personally hunt down the person you thought betrayed your parents."

"Still am," said Harry.

"No," said Lupin. "That's my task now. I promised him." He almost smiled.

"But you, Harry," he continued. "You have got to realise you'll be fighting more than Lord Voldemort. There's a reason Lord Voldemort rose to such unfathomable power. He couldn't have done this without the rest of us. You see what the system is capable of whenever we get a tiny bit scared. Soul sucking demons are set on school children. Prisoners are relentlessly tortured. Many die before their time is up. No trials People like Lucius Malfoy can buy a death sentence because a hippogriff annoyed their son. This is a system that's just waiting for someone to rise to power. Worse, it's doing his job for him."

"I don't think people understand their role in this," said Harry. He didn't know if that made things better, or worse.

"No," said Lupin. "They distract themselves with manufactured fear. They micromanage the thickness of cauldron bottoms, and they change seats when Half-Bloods sit next to them on the Knight Bus. This is what you're up against, Harry. You're fighting Lord Voldemort, true, but you've got to realise that the government is not on your side, and that the people you're saving choose to be completely irrational."

Harry looked up and realised they were back at the lift. The long, terrible corridor lay behind them, finally, and he still hadn't asked the most important question.

"Professor," said Harry quietly as the lift doors close. "How come you can do them? Patronuses?"

Lupin smiled. "It's not like I kept that a secret from you," he said drily. "Happy memories. I have Sirius and your parents to thank for most of them."

"But aren't they also sad?" said Harry. "Because they're over, I mean. I -" He was not too sure whether that sentence appropriately conveyed the complicated thoughts he'd had on the subject previously. But it turned out he didn't have to, because Lupin understood anyway.

"Everything is over eventually," said Lupin. "But just because it's sad, doesn't mean it can't be happy at the same time. And if it hurts to bring up that memory, well then, that's part of growing up. I'm sorry, I should have explained that better. To the lobby," he addressed the lift.

They arrived there in silence. "I'm still not sure I fully understand," admitted Harry, when the doors opened.

"Then you know what you have to do," said Lupin.

"Yes," said Harry, with a sigh. "Practise."

"Exactly," said Lupin. "Happy memories. Repeat them in your head. Keep your friends by your side, make some new happy memories. The Patronus charm will come to you in time. Some of us just have to work harder for it."

Harry looked at him from the side. The man seemed tired, and shabby, but not hopeless. Never that. "Thanks, Professor," he said.

"Best not call me that anymore," said Lupin. "I'll resign first thing tomorrow. Didn't get around to it in all the chaos. But as long as I still have some authority over you, Harry – practise being happy. I'll be in touch."

* * *

Whenever Harry entered the room in the following years, it wasn't happy memories he brought. He went when it all got too much, when he needed to speak into the void, let it draw out what he himself couldn't name. He went in his fourth year, after Cedric died, after Voldemort rose from the dead and decided to celebrate the occasion by torturing Harry. He went in his fifth year, after Hagrid perished in the Department of Mysteries because Voldemort knew Harry would go to any lengths to protect him. He went in his sixth year, after Albus Dumbledore was murdered by Severus Snape. Harry's visits with Sirius were marked by the avoidable deaths of Voldemort's rise, the should-haves and the should-not-haves of a survivor. And Sirius just listened.

Every time, Sirius stood in that same spot, not looking at anything. Every time, he looked thinner than he did before. His too-short cloak started greying and fraying over the years, his once handsome face retreated into the hood. It was always summer when they met, but the room got colder every year.

* * *

The last time Harry visited was on his eighteenth birthday. He brought Ron and Hermione, because there was safety in numbers. There was ice on the window, even though it was July, and Sirius was still standing there, his cloak moving in an invisible wind. His face was hidden in shadows underneath the hood.

"Hi Sirius," he said, and beside him, Ron and Hermione uttered similar greetings.

Well, there was no painless way to say this, so he thought he'd make it quick.

"I know Lupin has been visiting you every week," he began.

Was there a tiny acknowledgement? A turning of the head? It didn't alleviate Harry's worries, on the contrary. But he, Ron, and Hermione all had their wands.

"I'm very sorry, Sirius, but Lupin won't come here anymore," continued Harry. "He died in the battle against Lord Voldemort. We won, but… we won at a price."

This time it was unmistakeable. That head turned. Shadows danced underneath the hood. Harry barely recognised that cloak as his anymore.

"Still," continued Harry, addressing the basic program, that tiny bit of Sirius that he'd been trying to convince himself was still in there somehow. "Lord Voldemort is gone, forever. So is Peter Pettigrew. So is Bellatrix Lestrange. So is Severus Snape. He was a good man, though I expect you won't believe it. We couldn't have done it without him."

"Your brother, too," said Ron.

"Yeah," said Harry. "Regulus wasn't a Death Eater who got scared. He defied Lord Voldemort, and died for it. He was a good kid, a brave kid, and I think you might be glad to hear it. The price was high, but we won. It's your win, as well, and it's long overdue, and we thank you for all you did."

There was silence, but it was attentive. It wasn't a void. It wasn't nothing. Harry could feel it in his teeth, he just didn't know _what_ it was.

"It's okay, Sirius," said Hermione softly, her hand gripping her wand tightly. "You can leave now. We'll be fine."

"Yeah," said Ron. "We're prepared. Harry has taught us. It's okay to let go."

It was staring at them now. Harry was shaking with cold, but there was none of the bone-chilling fear. None of the voices. None of the screams. He looked at Hermione. Maybe Sirius needed convincing. Maybe he didn't understand. Maybe he needed an explanation.

"Four years ago," said Hermione, "I wrote an essay. So many of my stories start like this." She smiled. "It was for Professor Lupin. Compare and contrast different theories on where Dementors come from. There are so many, but none of them made sense."

"Yeah," said Ron. "I mean, Boggarts? Seriously?"

"But that was all the scholars had to offer on the subject of Dementors," said Hermione. "Years later, I read a story. It was in _The Tales of Beedle the Bard_. Surprisingly helpful book. That story said that the first Dementor was just a wizard, a skilled Legilimens. A sad and scary man. All he craved was happiness, but there was none in him. So he started taking them where he could, happy memories, and he didn't give them back. He was in a woman's head when she died from the shock, and without a living substrate, the sad man's soul died with her. All that was left of him was a husk, and a hunger. He devoured happiness, and then he devoured souls, and his victims, in time, did the same. But it takes a while for that last spark to die. About a year, for most."

"We know what you did," said Harry. "You held out for four years. You guarded the void, and you listened. We can only imagine how hard it must have been. I know why you did it, Sirius, I'm a godfather now, too. I bet Lupin told you about little Teddy. But it's okay, Sirius. I promise we'll be fine."

No reaction, and Harry was horribly reminded of the first time he had been here. Maybe Sirius, or what's left of him, needed a nudge.

"I'll show you," he said. "I can do it now." His left hand reached for Hermione's arm, and on his right side, Ron lay a hand on his shoulder. "I have my best friends by my side," he said. "Voldemort is gone, the war is over. There's so much happiness I could explode. So much sadness, too, but a good man taught me there's never one without the other. _Expecto Patronum_."

He didn't shout, he didn't have to. The stag emerged from his wand, stood proudly in the middle of the room before moving over to Sirius, nudging his shoulder with his nose. A light made of happiness and memory and relief, lighting up that skeletal face one last time.

"Remember Prongs?" said Harry, who forced himself to look at that face. "He's your best friend, and he's showing you the way home."

It wasn't dramatic. Important things rarely were. There was a sound, like a person breathing out one last time. Then the stag took a giant leap and galloped off through the closed window.

The hooded shape that was formerly Sirius was swaying in a non-existent wind. It drew a rattling breath. Harry smiled, looked at Ron, then at Hermione.

"We've defeated Voldemort and his entire army," he said. "I think we can deal with one more bloody Dementor."

* * *

 _The End._


End file.
